Internal-combustion engine



April 2, 1929. w. R. ATKESON INTERNAL COMBUSTION ENGINE Filed April 18, 1927 5 Sheets-Sheet l April 2, 1929. W, R, ATKESON 1,707,779

INTERNAL COMBUSTION ENGINE Filed April 18, 1927 5 Sheets-Sheet 2 April 2, 1929. W. R. ATKESON INTERNAL COMBUSTION ENGINE Filed April 18, 1927 5 Sheets-Sheet 5 Sheets-Sheet 4 Aprll 2, 1929. w. R. ATKESON INTERNAL coMBUsToN ENGINE Filed April 18, 192'? @y WNWNW April 2, 1929. w. R. ATKESON INTERNAL COMBUSTION ENGINE Filed April 18, 1927 5 Sheets-Sheet such engines wherein the Patented- Apr'. 2, 1929.

Application filed April 18,` 1927. Serial No. 184,741.

This invention relates to internal combustion engines and especially' to that class of cylinders are parallel to and surround the engine shaft. Y

The objects of this-invention are; to intcrease the efiiciency of such engines; to decrease vibrations manufacture.

I attain the increase in eiiiciency by means -of the long strokeand small bore of the cylinf der with the resltinghigh piston speed: also the peculiar relations between the pistons and shaft result in a relativelylow shaft speed. The elciency the fact that the peripheral speed of the rotor` is high and the friction loss thereon is low;

and also by the peculiar `valve motion whichis equivalent to a substantial increase in the diameter of -the valve. The decrease in viration of the machine is attained by the static balance of all moving parts lin all positions, and by the substantial dynamic bal--l ance thereof. The decrease in the cost of manufacturing of the machine is attained by the reduction of moving parts thereof as well as by the duplication of parts throughout themachine, there being no rightand lefthand construction therein.

Other objects are,l first, to reduce the wear of the cylinders by removing all torque therefrom; second, to eliminate spur gears for i to provide a special Constructed under V Y form of the rotor driving Athe valve operating apparatus; third,-

mecha'nism for operating the valves whereby they are given anfintermittent motion,fbeing opened and closed suddenly and being held open a substantial time instead of opening and closing with a substantially continuous movement as usually present practice, thereby diminishing the throttlingrraction of the valves on the' flowing gases and producing an leffect equivalent to a much larger valve;

fourth, to operate, with consecutivel action,

all parts of the cycles in each cyl'knder in each reduce the end of the machine; fifth, .weight per horse power of Isuch an engine and especially to reduce the weight of its reciprocating parts; sixth, to reduce shock and vibration in the machine by the special cam grooves, said 'grooves being formed with theircenter lines on reversed parabolas whereby yuniform acceleration and retardation of the pistons is at- 'tained; and seventh, to reduce the friction between each piston and the rotor and to narand 'to decreasethe cost of7 A substantially two is further increasedbyand in section to reveal taken inthe directions indicated by row downthe rotor whereby its wearing qual-` y ities are increased.

AIn the particular form of engine illustrated and described herein eight cylinders are'` i mounted inl four opposed pairs, which arrangement results in eight power-strokes to the cycle of two revolutions of the shaft, each power-stroke applying itspower through right angles thereb maklng 1440 degrees of power-stroke in 20 degrees of revolution and thereby giving'sa practically constanttorque throughout the whole revolution. l 1

I 'attain these and other objects .by the' devices, mechanisms, and arrangements illus- Y Fig. 1 isa plan view of my engine as viewed on a line lying at 45 degrees from the vertical, and showing a part thereof broken away the interior thereof: Fig. 2 is an elevation of the engineshaft and rotor; Fig. 3 is a section of the "shaft on the lineS-S in Fig. 2 showing the duplex-camoperating wheels which control the motion of the intake valve cam; Fig. 4 is a Vsimilar View onthe line 4`4 in Fig. 2 showing theduplex cani-operating wheelswhih control the motion of the exhaustvalve cam; Fig. 5 is a plan I View of the-machinevshowing a part thereof in section and showing a portion of one end thereof removed from the frame; F i0. (3 is a diagrammatic illustration showing t e positions of the four ydouble pistons in successive `quarter-turns in two revolutions of the shaft;

Figs. 7 and`8 are ysimultaneous diagrams of the successiye states of the gas in t-he two cylinders atzopposite ends of any double piston,

the ar- 9 is an end elevation of my rows thereon A; Fig.

showing the valve mechaimprovedl engine,

nism of one of the 10 is a section on the line 10-10 in Fig. 5; Fig. l1 is a section on the line 11-1`1 in Fig. 5; Fig. 12 is a view of the development of the cam surface of therotor showing simultaneous positions of the four double pistons; Fig. 13 is an elevation of lons as viewed from the engine shaft; Figs. 14, 15, and 16 are sections of t-he said double piston taken respectively on the lines 14%14, 15,-15, and 16-16, in Fi 13; Fig. 17 is a longitudinal section of eit ier valve cam apparatus, demounted from the engine shaft; Figs. 18and 19 are cross sections thereof cylinders, in section; Fig.

one of the double pislaken m are lines 12s-1s, and 1919, in Fig.

tached to' the engine support. The drum 1 is provide-d with circular flanges 3, on each end. Two frame plates 4 close the ends of the drum 1 and are secured to the said flanges 3, and cach is provided with a central bearing 5 for the engine shaft.

Four engine cylinders are mounted on each of the said frame tplates 4, those on the one hand being in axial alinement with those on the other hand, all of the said cylinders being symmetrically arranged yabout the central axis of the engine and equidistant therefrom.v Each of the said vpairs of cylinders contains inside ofthe drum 1 and which engages the i cam grooves of the rotor mounted wit-hin the .55. their latusrecta, said latusrecta lying in-a through each phase drum. Allof the cylinders on one end of the machine have their valves controlled by a single 'pair of valve cam actuating wheels and therefore each cylinder 'in succession passes of the cycle. It will therefore be understood that in the herein description of one cylinder, or one pair of cylinders, or of one set of cylinders, that the description equally applies to the other cylinders or pairs of cylinders, or set of cylinders,

The shaft 6, passes centrally throughthe machine from end to end, and is supported therein in the centralbearings 5 as welll as in thev hereinafter described apparatus for opere ating the valves, .positioned at both ends of the engine. The shaft. 6 has the rotor,y 7 mounted on its center between the plates 4 vof the Iframe and between the bearings 5, and

- is Aprovi-ded with` similar valve cam-sleeves 8 at eac-h end. A H J f n Referring particularly `to Fig. 12, which shows the developed surface of the rotor 7 with the pistonslaid thereon,`theouter cylindricalwsurface lof the rotor 7 isygrooved forming threads betweenthe grooves 9. The guide curve used in laying ont the grooves 9 consists of two parabolas laid upon the surface of the rotor 7 and tangent at the ends of plane normal to the axis ofthe rotor. The

grooves are equidistant from each other l,and arallel. The layout curve may bethe center ine of the groove,if desired, but not necessarily, the essential feature being that such.'

groove consists oftwo or more parabolas tangent to straight lines connecting them. This layout is intended to cover a case -where a layout 'curve sov composed of two or more form, thus eliminating longitudinal shock in the machine. y

The cylinders 10 extend out from the plate V4,`at rightanglesthereto, land are provided lwith suitable heads 11 and are secured to the said plate 4 by means of bolts 12 in the usual way. Each cylinder is surrounded by a suitable jacket 13 clamped between andan outer plate 14, adjacent, the` said head 11, thereby forming a water chamber around the cylinder.

Referring particularly to Figs. 1 and 13 it will be seen that the double piston 15, which reciprocates in the two opposite alined cylinders 10,1s provided at each end with suitable f piston rings in the'usual manner and that one double piston which xtends acrossA thef the portion between the said ends is of special shape. The length of the piston from end to end is slightly greater than the length of one cylinder 1() together with the width of rotor 7. The part immediately adjacent the piston ends is especially illustrated in Fig. 14 and is hollow and its outer surface is cylindrical except for a 'short concave portion. `In general `the plate 4 the shape of the central part of the double piston' 1 5 is semicylindrical, but it isA lightened by means of cavities 16, and is shown fparticularly in Fig. 15. The surfaces -termi nating the 'semicylindrical portion are ycurved on the radius of the rotor. 7 and formv shoulders 17 rwhich bear thereon and which prevent the piston from rotating in the cylinder under the torque strainV produced by the rotor. Fivelugs or-fingers -18 project inward from the above described semicylindrical body, between the above cavities,`16, and each comprises a vsubstantially diamond-shaped figure having its two centralcorners rounded,

Figs. 12 and'13. Thesection of these fingersv v lisUparticul-arly illustrated in Fig.- 16. -lhe fingers are preferably provided with avcentral. hole for the purpose of lightening them,

The distance 'between thel centers of thefiingers 18 is exactly equal to the distance betweenthevvv centers of the above described grooves 9--in the rotor17 in a line parallel with' the shaft.. Thus it will be seen that'when the Y.

piston 15 moves in the cylinders 1 0 it applies a longitudinal pressure 'tol'the rotorv and, since the walls of thel grooves 9 are at 'an angle to the direction of motion of the piston 15 and fingers 18, 1t follows thatsuch' motion of the piston induces alateral and ltherefore rotary y motlon to the rotor 7. As clearly seen inthe drawings, three fingers 18 are always in contact with thelwalls of thegrooves 9 and thus it isxpossible tohave the stroke'of the lpiston ly shown in. Fig.

i ating devicesi considerably longer than width of the rotor As aboveV stated, the said fingers 18 are substantially diamondshaped, belng formed of two diagonally opposite pairs of straight portions 19., making a right angle to each other, said pairs being joined'by rounded portions 20, made on the radius of half the distance between the Vopposite ends of such straight portions 19. Therefore, by refer# lring lto Fig. 1/2, it will be seen that 'during ton is transmitted along a contact line onsaid curvedisurfaee 20, and groove 9; said contact line'rocks back and forth from one straight surface 19 to the other and back again, thereby reducing thewearon the .grooves 9 and t e lingers 18."

Each cylinder 10 is l1 containing awhich lies substantially at right angles to the radial line from the shaft'to the cylinder, as shown in the upper right hand corner of F ig; 9. Each combustion chamber 21 is provided witli an intake valve 22 controlling the intake passage 23, and with any exhaust valve 24 controlling the'exhaust lpassage 25. The valves 22 and 24 are side by side as clear- 9. A spark plug 26 yis screwed into the.combustion chamber 21 immediately adjacent to the intake valve 22. The valves 22 and 24 are of the usual. form for such rengines and are closed under-,the action of helical valve springs 27 ,surrounding the valve stems 28, and areopenedby the motion of the-respective valve cams, herein-- after described, one such cam being provided for each valve as clearly shown in Fig. 9

On eachend of the shaft 6, at a point in `line withthe valve. stems v28, of all the valves 22 and 24 are mounted duplicate valve-oper These devices are set lying 1n the same direction von the shaft 6 but vthat on one endis rotated. 180degrees from that on theo other endof the shaft. Ea l1 comprises a sleeve 8, secured on the shal suitable key 29 and .two pairs of mentary `or duplex cam-operating mounted on provided with a head -complewheels The two duplex cam-'operatingwheels 30 and 3l at the left end of the sleeve form the mechanism forwactuating the intake valve camf32 vhile the tWo duplexcaimoperating while the other wheels 33 and 34-atthe .right end of the sleeve form the actuating mechanism for the exhaust valve cam ,35. As shown,particularly in Figs. l, 5, and 17, the intake valve cani 32 and the exhaust valve cam'- 35 are mounted between the central walls 36 of the duplex cam box and 'one pairs of wheels 30 and 31 lie in one end of. said box pair of vcam-operating wheels 33 and 34 lie in the other endlof the box. One said central wall 36, adjacent-to the outer frame plate 14,4is'square (Fig. `9.) and'is attached to said plate 14 byboltjsiat its corcombustion chamberl 2lv the ends ,of the said sleeve 8.

camfoperating b ners (Figs. `5 and 9). v The valve cams 32 and-35 are identical for all'the valves in the engine. Th lve cams are perhaps best illustrated in Figs. 1 7 a shank 37, one end of which lies 1n one of the above-mentioned extending on both sides of the said shank 37. The teeth open` the valve and the close it. The duplex 30 and 3l',

cam 32 each compr1se,v1n essence, a yoneteeth 39. operate, to cam-actuating wheels equal radii, one Wheel being opposite to the short radius ofthe other wheel and the step or impact face of one tooth being in alinement with the l step or impact facek o the other Wheel. two said steps of each i the number of degrees which it is desired th t the intake valve 22 may be opened or closed, as the case may be. The' cam-operating wheel 30 engages the teeth 38 of the shank v37 while the complementary wheel 32 en ga es the teeth 39 thereof. t imilarlythe duplex cam-actuating wheels 33 and 34, which control the exhaust valve cam 35, are similar to the above described cam-actuating wheels y30 and 31 except that therein, which govern' the exhaust, valve 24 isopened diffe-rent from thecorresponding points in the wheels 30 and 31. Also themounting of Figs. 18to 23. J

the two sets of# duplex camactuating wheels in several successive positions (180 apart) together with one .pair of valve operating devices eomprisingthe shanks 37 with the cams 31 and. 351and the above-described lugs or teeth 3 8,and 39. In Fig. 20 the position of the Ishaft 6 is such that it has turned between ten 'and fifteendegrees beyond the vertical, as shown in Figs'. 7 and 8, at which time the just completed exhausting the' gases, the exhaust'valve24has just ..closed, and the intake valve 22 is being opened.

turned to close th'e exhaust valve24 and lies in av substantially tangential directionl relatively to the center of the shaft 6, and is stationary, and the intake valve cam 32 is be- Which controlthe intake valve ln Figs.v 20'to 23, inclusive, I have shown- The exhaust valve cam 35 has *beenv to 23 and each comprise I 38 operate to v said cam vshank 37, and, simultaneously,

rstep or impact face of the-'said 'wheel 31.

' liaust valve 24,

lsimultaneously the intake of the piston. In Fig.

This represents the position of the valves when the piston is drawing the explosive mixture into the cylinder controlled thereby. In Fig. 21 the shaft 6 has turned throuofh 180O and therefore is from ten to fifteen (I grecs beyond the vertical as shown in Figs. 7 and 8. In this position the exhaust valve cam 35 has again been actuated by the impact face of the cam-operating wheel 33 'engaging one of the teeth 3,8 to turn the shank 37 so that both the teeth 38 lie tangential to the center ofthe shaft and said valve cam 35 is pointed inward, substantially parallel with theaxis'of thevalve stem, and valve-cam 32 has been turned down at right angles to its valvevopening position and, therefore, the said intake valve 22 has been closed, the impact faceof the cam operating'wheel 31 having engaged the tooth 39 to turn'the shank 37 an. tofbring both teeth 39 into tangential position relatively to the center of the shaft 6. This represents thel position of the valves when the piston is compressing the gases in the cylinder. In Fig. 22 the shaft 6 has again turned through two right angles and occupiesvthe same position that it does in Fig. 20, but the two valve cams 32 and 35 are each in positions opposite to those illustrated in-Fig. 20. In this case both of the valves 22 and 24 controlled by the cams 32 and 35 are still closed. This represents the position of the parts during the firing stroke 23 the shaft 6 has again turned through two right angles and the cam-operating wheels occupy the saine positions as` illustrated; in Fig. 21. In this case the exhaust valve`cam 35 has just been turnedto point outward to open the said exwhile the intake valve cam 32 has also been turned through a right angle but the intake'valve during the exhaust stroke of the piston.

It will be observed from the drawings, especially Figst and 39, which are mounted on the several shanks 37 are formed with two convex and two concave surfaces. The two convex or end surfaces of the teeth are circular about the center of the said shank 37, while the two concave surfaces which form the sides of the teeth are circular and have an external radine equal to the radius from the center .37 and of the ing valves.

l 22 remains closed.y This represents the position of the-parts:

' being moved to its next position,

18 to 23that the teeth 38' each of the valve .cam

of the shaft 6 to the several cam operating wheels 30, 31, 33, and 34. The above-mentioned convex surfaces are formed at a radius extending from the center of the'shank 37 to, or near to, the

outer surface of the inner surface of the said cam-operating l wheels, as shown for instance in Fig. 19. When these lteeth 38 and 39 occupy their radial positions they are inactive but are adapted to be engaged by the approaching impact face of the cam-operating wheels, when, it

reaches it, and .the shank 37 is therefore adapted tobe turned through one right angle by the said impact face asit passes. Vhen the said tooth however occupies a tangential position it, and its opposite tooth, lie i on the outer surface of the cam-operating wheel, andvtherefore slides thereon. This fact prevents any vibration of the said shank valve cam or Each valve cam is therefore locked, in any one of its four positions, during substantially one-half revolution of the shaft 6 and, if the said cam has raised its valve, it then holds that valvev open and stationary during substantially one-half of the revolution of the shaft 6.

Thus it will be seen that the several valves are each opened once in two revolutions of the shaft 6 and remains open for about oned half a revolution of the shaft, yand that the opening and closing motions .of the said valves is very rapid, taking place while the shaft 6 is turnin through something like twenty degrees. nd also it'will be understood that since the said valve is held Wide open, and stationary, during the greater part of its opened period, the effectiveness of the opening is very materially increased over those valves which move continuously, from closed to full open and back to closed positions, because the valve itself, in my. invention, does notthrottle the valve passage during the time that it is supposed to be opening as is the case in such continuously mov- It might be thought that the. sudden motion of the valves would create vi- 'bration and noise when the impact face engages and turns the tooth 38 or 39 but, by properly shapingv the said impact faces so that the complementary tooth will slide down one impact fact while the other is `being turned, in other words unlocking the shanki of the valve. v

Thus it will be seen that while the engine shaft 6 is making two complete revolutions quarter turns and each of these quarter turns Shanks 37 makes four` on theinside of l i `the engine shaft is turning through a very few degrees, and that the said shanks 37 do not turn except when the steps in the camactuating wheels engage the teeth 38 or .39 thereon. It will also be seen that the four cylinders-on each side of the en ine act in consecutive order. As shown in ig. 6 it is evident that the cylinders marked 1, 2, 3, 4, on one side of the engine fire in that order during one revolution of the shaft while the cylinders marked 7, 8, 5, 6, -fire in' that order during the second revolution of the shaft.

It will be observed in the several drawings, especially in Figs. 1 and 11, that the central part of each p i'ston travels across the drum l in the center of the machine and rides in a groove 41 formed in an enlargement 42 on the inner side of the said drum 1, and it will also be observed, especially from Fig. 15, that that portion of the piston has shoulders 17 formed thereon, as above described,

which shoulders are adapted to engage the outer surface or threads Vofthe rotor 7 and which preventthe piston 15 from turning in the cylinder 10er in the said groove 41. Also, it will be understood from Fig. 11, that the torque, or side pressure of the rotor on the piston, is all taken up in the said groove 41- and is not transmitted to the cylinder 10, and that therefore, the said cylinder is relieved of allx torque strain.

'It is, of course, understood that thrust bearings 43 are inserted between the engine frame plate 4 and the boss of the said rotor 7 whereby the longitudinal thrust of the piston on the rotor is transmitted to the frame.

In my design proper lubrication is easily accomplished as shown on the large drawing. An oil reservoir may be provided at the lowest point of the engine frame, orxin any suitable location; any one of the several successful oil pumps can be geared to-the main shaft and pump oil to the piston through the engine frame and through the hollow fingers 18, or roller shafts if rollers are used, and into the grooves between the threads on the rotor where the centrifugal force will throw the oil out and over the whole surface of the rotor. Ample oil will drag into the cylinders with the pistons. The oil surplus will gather the engine frame and run down over the thrust bearings and down to the bottom of the engine frame and back tothe pump. The valve gear may also be.

suy plied -with oil from the same pump.

t will vbe understood that many changes in detail may be ing from the spirit of the invention. For example, the cylinders 10 could readily be made to rotate about the central shaft 6, this being common in the art, and the appended claims are intended to cover any such4 variations and modificatlons.

-polnts around said shaft pact face passes,

resorted to without depart- Havin therefore described what I c aim is p m1. In an engine,-the combination with a fixed frame; a cylinder mounted thereon; a pair of spring closed poppet valves; a shaft mounted in said frame; a pair of valve cams my invention,

mounted in said frame, each onan axis paral,

lel with said shaft, each said cam adapted to open one said valve; and 4two sets of means each interposed between said shaft and one .said valve cam, whereby leach said valve cam 1n saidl frame; a valve cam adapted to open.

said valve and having a shank mounted yin said frame on an airisv parallel with said shaft; a pair of two-toothed lugs on the shank of said valve cam, said lugs extending from said shank at right angles to each other; and a pair of one-toothed wheels mounted' on said shaft and having their teeth at different and each adapted to engage one vsaid two-toothed lugs, whereby said cam is turned a quarter revolution by eah said wheels and a half revolution by both said wheels in one revolution of said shaft.

3, In an engine,I the combination with a fixed frame; a vcylinder mounted thereon; a spring closed poppet'valve; a shaft mounted in said frame; a valve cam adapted to open said valve and having a shank mounted in said frame on an axis parallel with said shaft; a pair of one-toothed wheels mounted on said shaft, the tooth of one being complementary to the tooth ofthe other, each said tooth on one wheel starting where the tooth on the other wheel ends; and a pair of two-toothed lugs onthe shank of said valve cam, said lugs extending from the shank at right angles to each other, each adapted to be actuated by the impact face of the tooth ofl one said wheel when in its radial or set position as said imof said tooth when the other lug 1s in set position, whereby said valve cam is intermitently actauted and is held in itsturned position until again actuated. 4. In an engine, a cylinder, a shaft having its axis parallel with the axis of said cylinder and rotatable with reference thereto, a cam block carried by said shaft and having a groove formed therein, thecenter line of said groove being composed of two reversed paraolic curves, a piston reciprocating in said cylinder and means carried by sald piston and engaging said cam groove.

5. In an engine, a cylinder, a drive shaft having its axis parallel with the axis of said the combination with a and to lie on the outer face spect thereto,

cylinder and rotatable reference thereto,

a cam block carried by sald shaft and having a plurality of parallel cam grooves formed in rality of spaced finger lugs, a lug engaging at least one Wall of each cam groove at all times.

6. In an engine, in combination, a cylinder, a drive shaft having its axis parallel to the axis of said cylinder andl rotatable with rea valve communicating with said cylinder,and a valve cam shaft having its axis parallel to said shaft and fixed Awith reference to said cylinder, said shaft being operated by therelative rotation of said shaft with respect to the cylinder. l

7 In an engine, in combination, a fixed cyl inder, a rotat-ableidrive shaft having its axis parallel to the axis of said cylinder, a valve communicating. with said cylinder, and a valve cam shaft operated by lsaid drive shaft and having its axis xed and parallel to said drive shaft. 8. In an engine, a cylinder, a rotor shaft having its axis parallel with the axis of said cylinder, and rotatable with reference thereto, a cam block carried by said -shaft and havi ing a groove formed therein, the layout curve of said groove comprising two parabolic curves tangent at the ends of theiry latusrecta,

said latusrecta lying in a plane normal to the axis of the rotor shaft, a piston reciprocating in said cylinder, and means carried-by said s piston and engaging said cam groove. Whereby axialmovement of said piston 1s trans- In testimony whereof I aiiix my signature 35 formed'into rotary motion of said rotor shaft WALTER A'IKESON. 

